Retesting Reveals Mad Cow Case

New tests have confirmed that a Texas animal that federal officials earlier declared to be free of mad cow disease did have the brain-wasting ailment, the U.S. Agriculture Department announced yesterday.

The definitive testing, done in England over the past two weeks, showed that the ailing animal, first flagged as suspicious in November, was infected with mad cow disease. The animal was retested after the USDA's inspector general requested the additional check because of continuing concerns about the sample dismissed by the agency.

USDA Secretary Mike Johanns said that officials are just now trying to learn more about the origins of the animal, but that there is no indication that it was imported, as was the only other animal to test positive for the disease in the United States. That would make the newly identified animal the first born in this country found to have mad cow disease.

Johanns sought yesterday to assure consumers that U.S. beef is safe, and that any suspect beef would have been kept off supermarket shelves.

But he acknowledged a number of embarrassing mistakes and oversights by the agency. In addition to misdiagnosing the diseased sample, officials apparently mislabeled the sample that tested positive, officials said. According to USDA's chief veterinarian, John Clifford, a tag describing the breed of the infected animal was apparently mislabeled, an error that has slowed the process of determining where the animal came from.

The lab in Weybridge, England, considered the world's best, made the diagnosis using two tests -- including one the USDA used when it declared the animal disease-free. USDA officials previously said that the diseased animal escaped their notice because they performed only an immunohistochemistry test, or IHC, and not a Western blot test. Yesterday, Johanns said that the Weybridge lab found the sample to be positive for mad cow disease using both types of test.

Johanns said that from now on, the agency will use both tests on all samples found to be suspicious on an initial, rapid screening test for the disease. About 388,000 animals have been subjected to that test, and only three have been found to be suspicious, Johanns said.

Scientists believe that mad cow disease is spread through the feeding of infected animal parts to other cattle. The United States banned that kind of feed in 1997, and Johanns said he believes the infected animal was born before that time.

In very rare cases, the disease has been passed on to humans who eat the infected meat, and the result was always fatal. There have been no known cases of the human variant of mad cow disease in this country.

Yesterday's announcement drew immediate and sharp criticism of the administration's handling of mad cow disease, or bovine spongiform encephalopathy (BSE). The beef industry lost billions of dollars in exports when the first mad cow case was found, and critics said the administration has sought to minimize additional threats to protect the industry from a second crisis.

Over the past week, some industry representatives had questioned the inspector general's authority to order the additional tests that ultimately found the positive sample, and Johanns publicly agreed with some of their criticism.

"Now we know why USDA resisted having the suspect animal subjected to the most sophisticated BSE test," said Carol Tucker Foreman of the Consumer Federation of America. "They were afraid the truth would come out. The public and the industry know that this animal was infected with BSE only because the USDA office of inspector general insisted that the additional test be done."